The project concerns the evaluation of enzymes as reagents for organic functional group transformation and the utilization of these transformations for the synthesis of antibiotic compounds and environmentally benign molecules. In particular the project evaluates the use of oxidizing enzymes and lipases for the synthesis of macrocyclic lactones and the application of lipases for selective chemical modification of carbohydrates. The long range objectives are to develop environmentally benign chemical synthesis and to prepare polymers which degrade to naturally occurring molecules. The specific aims are: (1) To develop enzymic methods for the Baeyer-Villiger oxidation of alpha- substituted-Beta-trimethylsilylcycloalkanones to lactone-alcohols, (2) To evaluate the use of lipases for the translactonization of lactone- alcohols, (3) to apply (1) and (2) in the synthesis of macrocylic antibiotic compounds, (4) To evaluate the regioselective and stereoselective differentiation of lipases in the acylation and deacylation of monosaccharides and acylated monosaccharides respectively, (5) To develop polymeric acyl transfer reagents, (6) To evaluate the effects of the acyl transfer reagent, temperature, and solvent on enzymic esterification of monosaccharides, (7) To apply (4), (5), and (6) to the selective chemical modification of polysaccharides.